The present invention is generally directed to a sense point circuit and more particularly to a sense point circuit for sensing the active or inactive condition of an electrical path as represented by the conduction or nonconduction of a solid state device.
Sense point circuits are well known. They find general application in telephone systems wherein the active or inactive conditions of electrical paths including relays or the like must be sensed in order to provide efficient and reliable telephone service. When the active or inactive conditions of relays are to be sensed, prior sense point circuits have been generally successful because mechanical relays provide inherent isolation between the sense point circuits and the relay contacts. However, with solid state switches and the like becoming increasingly popular, such sense point circuits are not so successful. The prior sense point circuits are generally unsuccessful because solid state switches or the like do not afford readily available isolation between the sense point circuits and the condition to be sensed.
It is therefore a general object of the present invention to provide a new and improved sense point circuit.
It is a more particular object of the present invention to provide a sense point circuit which senses the active or inactive condition of an electrical path which includes solid state devices while still providing sufficient isolation between the sense point circuit and the condition being sensed.